[Xen-devel] [PATCH v5 4/5] x86: fix indirect thunk usage of CONFIG_INDIRECT_THUNK

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

When indirect_thunk_asm.h is instantiated directly into assembly files
CONFIG_INDIRECT_THUNK might not be defined, and thus using .if against
it is wrong.

Add a check to define CONFIG_INDIRECT_THUNK to 0 if not defined, so
that using .if CONFIG_INDIRECT_THUNK is always correct.

This suppresses the following clang error:

<instantiation>:8:9: error: expected absolute expression
    .if CONFIG_INDIRECT_THUNK == 1
        ^
<instantiation>:1:1: note: while in macro instantiation
INDIRECT_BRANCH call %rdx
^
entry.S:589:9: note: while in macro instantiation
        INDIRECT_CALL %rdx
        ^

Note that this is a preparatory patch in order to enable clang's
integrated assembler, the integrated assembler is not yet enabled for
assembly files.

Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
Changes since v4:
 - Define CONFIG_INDIRECT_THUNK if not defined using an equation.
---
 xen/include/asm-x86/asm_defns.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/xen/include/asm-x86/asm_defns.h b/xen/include/asm-x86/asm_defns.h
index 6fc13d39d8..ebd2c88a1f 100644
--- a/xen/include/asm-x86/asm_defns.h
+++ b/xen/include/asm-x86/asm_defns.h
@@ -15,6 +15,9 @@
 #include <asm/alternative.h>
 
 #ifdef __ASSEMBLY__
+#ifndef CONFIG_INDIRECT_THUNK
+.equ CONFIG_INDIRECT_THUNK, 0
+#endif
 # include <asm/indirect_thunk_asm.h>
 #else
 asm ( "\t.equ CONFIG_INDIRECT_THUNK, "
-- 
2.16.1


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel